Physico-chemical surface water conditions of catchments with metallogenic origin: A contribution to the establishment of the EC Water Framework Directive 2000/60/EG in Germany Peter L. Neitzel1, Petra Schneider1, Helmut Schlumprecht2 1Hydroisotop-Piewak GmbH, Oberfrohnaer Str. 84, D-09117 Chemnitz 2Büro für Ökologische Studien, Alexanderstr. 5, D-95444 Bayreuth Abstract: For the realisation of the EC Framework Water Directive in Germany, the reference conditions of metals in surface waters have to be determined taking into consideration the so called surface water landscape. In catchments of metal- logenic origin metals and radionuclides like uranium influence the quality of the surface waters. In this study, the quality status of metallogenic (Ore Mountains, Harz, Rhine Slate Mountains) and other surface water landscapes were compared in order to differentiate factors influencing the natural background in similar geo- logical formations. Introduction In the year 2000 the EC Water Framework Directive (2000/60/EG) passed the par- liament of the European Community (EC), which then became legal law in all countries of the EC. The main objective of the EC-directive is to achieve a good quality of all surface, ground-, estuary and coastal waters. This includes an as- sessment of the chemical status of the surface waters (environmental quality stan- dards for nearly 30 priority compounds and substances) and a five-stage ecologi- cal classification of waters. According to the regulations three groups of characteristics are important for the European surface waters, namely: hydrobiol- ogy (priority), hydromorphology (supporting hydrobiology) and physico-chemical conditions (supporting hydrobiology). “High water quality” (class I) hence reflects natural conditions totally, while class II refers to “good water quality”. Addition- ally the maximum ecological potential is taken as reference for heavily modified and artificial water bodies (Irmer 2000). 78 Peter L. Neitzel et al. Within an investigation project, financed by the Environmental Federal Agency (UBA) of Germany, all available analytical data of low polluted or close to natural surface waters in 30 different water landscapes of Germany were collected and analysed by statistical methods (Schneider et al. 2002, Neitzel et al. 2002). The data base included summary and effect indices, major ions, salts and nutrients, heavy metals (Cd, Cr, Ni, Hg, Pb, U, Zn), as well as As and Cu. The aim of the study was the elaboration of a physico-chemical data base for the assessment of the natural background of surface water bodies in Germany (Neitzel et al. 2002). This data base was used to define the reference status according to their hydro- morphological and geological setting. Regarding the quality of surface waters, the EC Framework Water Directive requires the level 'good ecological and chemical quality' to be reached in the year 2016. In this study, the quality status of metal- logenic (Ore Mountains, Harz, Rhine Slate Mountains) and other surface water landscapes was compared in order to differentiate factors influencing the natural background in similar geological formations. Physico-chemical surface water assessment of catchments with metallogenic origin Assessment of physico-chemical data of surface waters In order to meet the requirements of the EC Framework Water Directive in Ger- many, reference concentrations (= natural background concentrations (Fergusson 1990)) of metals have to be determined taking into consideration the so called sur- face water landscape. In catchments of metallogenic origin, heavy metals and ra- dionuclides like uranium can influence the quality of the surface waters. As inves- tigations showed, the following geological formations were of metallogenic origin: granite, slate, gneiss, diabase, and Grauwacke. The data were compared to reference concentrations of metals and uranium in surface waters with low anthro- pogenic influence. Data pool LAWA (Länderarbeitsgemeinschaft Wasser/German Water Association) defined the reference status as natural background concentrations of a non-anthropogenic influenced catchments in 1998. The investigated data base of 560 measuring loca- tions of 30 different surface water body types contains 3.500 analytical data sets. All data were analysed using statistical methods. Mean, 10-, 50-, and 90-percentils as well as minimum and maximum values were calculated. The representative data base obtained the assessment of the sustainability of the environmental quality standards as defined by LAWA. Impact on groundwater from radionuclide emission Physico-chemical surface water conditions of catchments with metallogenic origin 79 Surface water landscapes with metallogenic origin Part of this study was the investigation of the quality status of metallogenic sur- face water landscapes. As the results of the physico-chemical data assessment show, the Ore Mountains, the Harz Mountains and the Rhine Slate Mountains dif- fer significantly in their metal content from the other catchment types. Hence the metallogenic surface water landscapes have to be given a special status. Results Main results of the investigation of all surface water landscapes Physico-chemical data of 30 different types of surface water landscapes were in- vestigated according to the surface water landscape classification of Briem (2001). The results of the statistical analysis show, that the surface water bodies in Ger- many can be summarised in six catchment types (Fig. 1): • bogs and bog riverside meadows • salinic catchment type • carbonatic-dolomitic catchment type • sandy-clayey catchment type • silicatic catchment type and • metallogenic catchment type Heavy metals bound to particular matter (based on 50 percentils) For all catchment types, with the exception of the metallogenic landscapes, the reference status of lead, chromium and mercury met the quality standards of class I (high water quality standard) of LAWA, while cadmium, copper, nickel and zinc values were found to be increased in all catchment types. A reference status for these parameters cannot be defined in the particular matter of metallogenic land- scapes with the exception of mercury. Heavy metals in the total liquid phase (based on 50 percentils) A reference status referring to high water quality standard (class I) was evaluated for following heavy metals: • chromium: all catchment types • copper and lead: carbonatic-dolomitic catchment type • nickel: all types excluding sandy-clayey catchment type and salinic type • zinc: carbonatic-dolomitic type, silicatic type, sandy-clayey catchment type Impact on groundwater from radionuclide emission 80 Peter L. Neitzel et al. Fig. 1. Aggregated surface water landscapes according to the results of the physico- chemical assessment. Impact on groundwater from radionuclide emission Physico-chemical surface water conditions of catchments with metallogenic origin 81 No reference status was found in whole Germany for cadmium and mercury con- sidering NOEC-standards (No Observed Effect Concentration) with respect to the most sensitive water organism. There are different causes for this situation: vari- ous diffuse and historical pools as atmospheric deposition, use of fertilizers and solution effects of acid rain in the soils. Metals/metalloides in the liquid phase (based on 50 percentils and means) No LAWA quality aims exist for aluminium, arsenic, barium, iron, cobalt, manga- nese and uranium. The results of the statistical analysis provide a data base that can be used do define a reference status for these parameters. These results also correspond to data found in literature. Main results of the investigation of the metallogenic catchment types The results of the investigation of the metallogenic catchment types in comparison to the quality class I (the natural background) of LAWA (1998) and the other sur- face water catchment types are summarized in the tables 1 and 2. Table 1. Metals in the suspended phase - comparison to the quality class I of LAWA (1998) (based on 50 percentiles) metal quality bogs and car- silicatic sandy- salinic metal- (mg/kg) aim class bog river- bonatic- catchment clayey type logenic I side mead- dolomitic type type type (LAWA) ows type lead ≤ 25 18 22 30 24 26 175 cadmium ≤ 0,3 1,0 0,4 0,5 0,3 1,0 17,5 copper ≤ 20 7,0 39 37 21 9,0 81 nickel ≤ 30 11 56 47 29 22 120 mercury ≤ 0,2 no data 0,1 0,2 0,1 no data 0,2 zinc ≤ 100 36 127 140 92 62 1100 Table 2. Metals in the liquid phase - comparison to the natural background of LAWA (1998) (based on 50 percentiles) metal natural bogs and car- silicatic sandy- salinic metall back- bog river- bonatic- catchment clayey type ogeni ground side dolomitic type type c type LAWA meadows type lead (µg/L) 0,4 - 1,7 1,0 1,4 1,0 0,9 1,0 2,1 cadmium (ng/L) 9 - 36 250 100 150 130 150 339 chromium (µg/L) 1,3 - 5 0,5 0,5 0,5 0,6 0,9 2,5 copper (µg/L) 0,5 - 2 4,8 1,4 1,3 0,9 4,0 2,4 nickel (µg/L) 0,6 – 2,2 2,0 1,3 1,8 2,0 4,7 5,6 mercury (ng/L) 5 - 20 50 100 500 50 20 188 zinc (µg/L) 1,8 - 7 10 5,0 13 5,0 12 28 Impact on groundwater from radionuclide emission 82 Peter L. Neitzel et al. An increased metal status in the liquid phase in comparison to the natural back- ground concentrations of the other surface water landscapes has to be considered for: • Ore Mountains: cadmium, copper, zinc, lead, • Harz Mountains: nickel, zinc, • Rhine Slate Mountains: nickel, zinc, lead, copper. The most increased metal status of all investigated geological metal rich forma- tions (granite, slate, gneiss, diabase, Grauwacke) was found in slate. To evaluate the reference status of surface waters of mixing catchment types and catchments with anthropogenic influence a runoff-concentration-analysis was calculated using the Hellmann-method. There was no usable result due to the variability and occur- rence probability of the catchment influences. Conclusions The results of the physico-chemical surface water assessment study provide the reference status of the metallogenic catchment types as base for the implementa- tion of the EC Water Framework Directive in Germany.